The anti——icing and de·-icing methods of insulator strings are still under laboratory studies while many technologies are applied in operation to overhead conductors.The anti—icing method using semiconducting ...The anti——icing and de·-icing methods of insulator strings are still under laboratory studies while many technologies are applied in operation to overhead conductors.The anti—icing method using semiconducting silicone rubber coating applied to the bottom side of the insulators could get good results in a climate chamber.However,the resistance of the coating is an important factor influencing the anti—icing performance of the coated insulators.Thus the coating resistance should be determined.展开更多
In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （...In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （ATR-FTIR） spectrum and X-ray photoelectron spectroscopy （XPS） were used to observe the variation of the functional groups of the modified SIR. Static contact angle （SCA） was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m^2 of original SIR sample to 2.94 mJ/m^2 of SIR sample treated by CF4 CCP modification at RF power of 200 W for a treatment time of 5 rnin. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si--F or Si--F2 and the fluoric groups of C--CFn induced by the methyl replacement reaction and residual methyl groups of SIR surface.展开更多
Silicone rubber gaskets are employed to keep fuel gases and oxidation in their own zones. Due to the viscosity and elasticity, the assembly force could relax when the silicone rubber is compressed in a proton exchange...Silicone rubber gaskets are employed to keep fuel gases and oxidation in their own zones. Due to the viscosity and elasticity, the assembly force could relax when the silicone rubber is compressed in a proton exchange membrane fuel cell. In this work, the stress relaxation behavior of silicone rubber samples is studied under different temperatures and simulated operating conditions. The results show that the stress relaxes exponentially with time at 25% strain level, especially at higher temperature or with higher acid concentration solution. The three-term Prony series can simulate the viscoelastic behavior well, and the Master curves are established by applying a time–temperature superposition method to estimate the life of the samples. It can save approximately 50% and 78% of the test time when an operating temperature and acid solution are chosen appropriately.展开更多
The use of polymer materials as electrical insulators on transmission and distribution lines has been increasing such as epoxy resin.Several advantages of using epoxy resin as an insulating material are its low densit...The use of polymer materials as electrical insulators on transmission and distribution lines has been increasing such as epoxy resin.Several advantages of using epoxy resin as an insulating material are its low density,better dielectric properties,and epoxy resin has higher volume resistivity than that of the glass and porcelain.However,epoxy resin has some disadvantages when it is used in tropical areas concerning with the humidity,high ultraviolet radiation, acid rain and effects of contaminants.Consequently,insulator surface will be easily damaged due to electrical tracking,which is indicated by the surface tracking.In this paper,the surface tracking on epoxy resin compound with silicon rubber has been investigated.The test was done based on the method of Inclined-Planed Tracking(IPT) IEC 587:1984 with NH_4C1 as contaminant.The test materials used were epoxy resins based on Diglycidyl Ether of Bisphenol A(DGEBA) and Methaphenylene Diamine(MPDA) compound with silicon rubber(SiR) with the dimensions of 50 mm×120 mm and the thickness of 6 mm.The flow rate of contaminant was 0.3 mL/min.The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes.The experimental results show that the contact angle of hydrophobic was affected by compound of silicon rubber.The surface tracking,time to tracking and discharge current were affected by applied voltage,contamination and contact angle.By using micro-cameras,the surface damage was detected. The severest damaged sample surface on a sample had small contact angle.On the other hand,samples with the greatest contact angle needed longer time to have surface damage in the surface discharge.This shows that it is more difficult for large contact angle samples or more hydrophobic to have surface discharge.Epoxy resin compound with silicon rubber has contact angle of hydrophobic greater than epoxy resin without silicon rubber.展开更多
文摘The anti——icing and de·-icing methods of insulator strings are still under laboratory studies while many technologies are applied in operation to overhead conductors.The anti—icing method using semiconducting silicone rubber coating applied to the bottom side of the insulators could get good results in a climate chamber.However,the resistance of the coating is an important factor influencing the anti—icing performance of the coated insulators.Thus the coating resistance should be determined.
基金Project(05JT1034) supported by the Plan of Science and Technology Bureau of Hunan Province,China
文摘In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （ATR-FTIR） spectrum and X-ray photoelectron spectroscopy （XPS） were used to observe the variation of the functional groups of the modified SIR. Static contact angle （SCA） was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m^2 of original SIR sample to 2.94 mJ/m^2 of SIR sample treated by CF4 CCP modification at RF power of 200 W for a treatment time of 5 rnin. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si--F or Si--F2 and the fluoric groups of C--CFn induced by the methyl replacement reaction and residual methyl groups of SIR surface.
基金Projects(51505212,51505211,11302097)supported by the National Natural Science Foundation of ChinaProject(XTCX201609)supported by the Open Research Fund of Jiangsu Collaborative Innovation Center for Smart Distribution Network,Nanjing Institute of Technology,China+3 种基金Project(1301060B)supported by the Postdoctoral Science Foundation of Jiangsu Province,ChinaProject(11KJD130001)supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions,ChinaProject(ZKJ201401)supported by the on-job Doctorate Foundation of Nanjing Institute of Technology,ChinaProject(JXKJ201511)supported by the Open Projects about Key Discipline in 2015,School of Mechanical Engineering,Nanjing Institute of Technology,China
文摘Silicone rubber gaskets are employed to keep fuel gases and oxidation in their own zones. Due to the viscosity and elasticity, the assembly force could relax when the silicone rubber is compressed in a proton exchange membrane fuel cell. In this work, the stress relaxation behavior of silicone rubber samples is studied under different temperatures and simulated operating conditions. The results show that the stress relaxes exponentially with time at 25% strain level, especially at higher temperature or with higher acid concentration solution. The three-term Prony series can simulate the viscoelastic behavior well, and the Master curves are established by applying a time–temperature superposition method to estimate the life of the samples. It can save approximately 50% and 78% of the test time when an operating temperature and acid solution are chosen appropriately.
文摘The use of polymer materials as electrical insulators on transmission and distribution lines has been increasing such as epoxy resin.Several advantages of using epoxy resin as an insulating material are its low density,better dielectric properties,and epoxy resin has higher volume resistivity than that of the glass and porcelain.However,epoxy resin has some disadvantages when it is used in tropical areas concerning with the humidity,high ultraviolet radiation, acid rain and effects of contaminants.Consequently,insulator surface will be easily damaged due to electrical tracking,which is indicated by the surface tracking.In this paper,the surface tracking on epoxy resin compound with silicon rubber has been investigated.The test was done based on the method of Inclined-Planed Tracking(IPT) IEC 587:1984 with NH_4C1 as contaminant.The test materials used were epoxy resins based on Diglycidyl Ether of Bisphenol A(DGEBA) and Methaphenylene Diamine(MPDA) compound with silicon rubber(SiR) with the dimensions of 50 mm×120 mm and the thickness of 6 mm.The flow rate of contaminant was 0.3 mL/min.The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes.The experimental results show that the contact angle of hydrophobic was affected by compound of silicon rubber.The surface tracking,time to tracking and discharge current were affected by applied voltage,contamination and contact angle.By using micro-cameras,the surface damage was detected. The severest damaged sample surface on a sample had small contact angle.On the other hand,samples with the greatest contact angle needed longer time to have surface damage in the surface discharge.This shows that it is more difficult for large contact angle samples or more hydrophobic to have surface discharge.Epoxy resin compound with silicon rubber has contact angle of hydrophobic greater than epoxy resin without silicon rubber.
